<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        html,body,div{
            margin: 0;
            padding: 0;
        }
        table{
            border-spacing: 0px;
            width: 100%;
            margin: 0 auto; /* 让元素居中对齐的技巧 */
        }
        .header{
            height: 80px;
            background-color: blueviolet;
        }
        .aside{
            height: 800px;
            width: 80px;
            background-color: yellow;
        }
        .section{
            width:880px;
            background-color: maroon;
        }
        .footer{
            height: 80px;
            background-color: silver;
        }
        
        
        
    </style>
</head>
<body>
    <table border="1">
        <tr class="header">
            <td colspan="2"></td>
            <!-- <td></td> -->
        </tr>
        <tr>
            <td class="aside"></td>
            <td class="section"></td>
        </tr>
        <tr class="footer">
            <td colspan="2"></td>
           <!--  <td></td> -->
        </tr>
    </table>
</body>
</html>